Thermally stimulated luminescence from rare-earth-doped barium copper oxides.

Abstract

We report the first thermally stimulated luminescence (TSL) and emission-spectra measurements of x-ray-induced defects in ${\mathrm{Ho}}_{1.5}{\mathrm{Ba}}_{1.5}{\mathrm{Cu}}_{2}{\mathrm{O}}_{x}$ and $\mathrm{Gd}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{x}$ in the temperature interval 80-300 K. The Gd-doped oxide exhibits a single TSL glow peak at 195 K with concomitant single-band emission with maximum at 500 nm. Two TSL glow peaks (160 and 172 K) are observed in ${\mathrm{Ho}}_{1.5}{\mathrm{Ba}}_{1.5}{\mathrm{Cu}}_{2}{\mathrm{O}}_{x}$, whose spectral emission is characterized by complex, temperature-dependent maxima at 450 and 660 nm. Possible defect mechanisms are discussed.